diff --git a/src/Controller/MainController.php b/src/Controller/MainController.php
index 3da9a49..c1582c7 100644
--- a/src/Controller/MainController.php
+++ b/src/Controller/MainController.php
@@ -64,7 +64,6 @@ final class MainController extends AbstractController
         foreach ($finder as $file) {
             $current = &$tree;
 
-            // Dunno why it is undefined, it works
             foreach (explode('/', $file->getRelativePath()) as $part) {
                 if ($part === '') break;
 
@@ -74,7 +73,9 @@ final class MainController extends AbstractController
                 $current = &$current[$part];
             }
 
-            $current[$file->getFilenameWithoutExtension()] = [];
+            if (!isset($current[$part])) {
+                $current[$file->getFilenameWithoutExtension()] = [];
+            }
         }
 
         return $this->render('main/index.html.twig', [